Tool retainer

ABSTRACT

A tool retainer adapted for impacting machines and comprising a latch mounted in a sleeve of resilient material. The latch is releasably locked in a tool securing position by resilient snap action.

United States Patent Ekstriim Oct. 7, 1975 1 TOOL RETAINER [75]Inventor: Giista Ivar Ekstriim, Nacka, Sweden [56] References Cited [73]Assignee: Atlas Copco Aktiebolag, Nacka, UNITED STTES PATENTS Sweden1,176,343 3/1916 Chnstiansen 279/191 2,298,719 10/1942 OFarrell 279/195[22] Filed: June 24, 1974 3,525,531 8/1970 Ekstrom et a1. 279/196 1 1..1 4 2, l [2 1 App NO 8 238 Primary Examiner-G11 We1denfeld Attorney,Agent, or Firm-Flynn & Frishauf [30] Foreign Application Priority DataJuly 11, 1973 United Kingdom 33159/73 [57] ABSTRACT A tool retaineradapted for impacting machines and [52] 279/l9'l; 279/1 403/300comprising a latch mounted in a s1eeve of resilient ma- I t C 2 1 3632terial. The latch is releasably locked in a tool securing n b t 58 Fieldof Search 279/191, 19.6, 19, 19.2, y Snap ac 279/19.5,1 Q, 77, 78;403/300, 305, 12 Clalms, 5 a g Figures 3 L Z I II III US. Patent Oct.7,1975 Sheet 2 of2 3,910,590

TOOL RETAINER This invention relates to a tool retainer, particularlyfor use with hand-held impacting machines.

SUMMARY OF THE INVENTION According to the invention, there is provided atool retainer for retaining a tool having a shank with a collar thereon,comprising a sleeve of resilient material, a latch for retaining thetool mounted in the sleeve, the latch having a working surface forabutting the collar of the tool to retain the tool, the latch beingmovable between an active position where it projects into the axialpassage through the sleeve to retain the tool and an inactive positionwhere it is substantially withdrawn from said axial passage to allowwithdrawal of the tool, and locking means for locking the latch in theactive position by snappingit past a portion of the sleeve.

It is an advantage of this invention that the tool retainer can be madefrom a small number of parts, and that insertion of the tool andsubsequent locking of the latch is a very simple operation.

Preferably, the latch is pivotable about a latch pin mounted in part ofthe resilient sleeve, so that impacts of the tool collar on the workingsurface of the latch are at least partly absorbed by the resilient latchmounting.

Preferably, the locking means is provided by a space between tworesilient lugs, the space having a wider portion of similar or largercross-section than a handle of the latch and a narrower portion throughwhich the handle can only pass when the lugs are resiliently displacedrelative to each other.

Preferably, the sleeve, locking means and latch pin mounting are allformed from one piece of resilient material.

Preferably, the sleeve rear end portion is secured around a relativelynon-resilient tool holder in which the rear end portion of the tool canslide.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be furtherdescribed, by way ings, in which:

FIG. 1 is a section through the end of an impacting machineincorporating a tool retainer in accordance with the invention;

FIG. 2 is a section on the line II-II of FIG. 1;

FIG. 3 is a section on the line III-III of FIG. 1;

FIG. 4 is a section through a second embodiment of an impacting machineincorporating a tool retainer;

FIG. 5 is a section on the line VV of FIG. 4.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS A sleeve 1 of resilientmaterial is fitted tightly around a tool holder 2 forming part of thehousing of an impacting machine such as a concrete breaker, a rock drillor the like. At its other end, the sleeve, has an axial passage 3 oflarger diameter than the diameter of a collar 4 of a tool shank 5. Thesleeve 1 may all be molded as a single piece, and can be a snap fit onthe tool holder 2. When it is necessary to separate the two parts,

, a special tool must be used. The tool shank 5 has a suitably shaped,preferably hexagonal portion 6 which is a sliding fit in the tool holder2.

Referring now to FIG. l-3, a latch 7 with a handle 8 is journalled on apivot pin 9, the pivot pin being of example, with reference to theaccompanying drawmounted in lugs 10 made of resilient material withresilient retaining shoulders 17. The latch 7 has a working surface 11arranged at right angles to the direction of movement of the tool, andthe sleeve 1 has a recess 12 with an abutment surface 16 for the surface11 to receive the working surface 11 when the latch is opened to allowthe tool to be inserted or removed.

The resilient material referred to above may for instance be a plasticmaterial such as caprolactan, polyether urethane, or other materials ofthe polyeth'er or polyester type.

FIG. 2 shows how the handle 8 is held in the locking means to retain theworking surface 11 in the working position. To secure the handle 8, lugs13,14 must be pushed apart sufficiently to allow the handle 8 to passbetween them, after which they snap back into position, and the handle 8is secured. The handle 8 can conveniently be operated by the operatorsfoot, and the rigidity of the lugs 13,14 is designed in accordance withthis.

To insert a tool into the impacting machine, the latch 7 is pivoted sothat the surface 11 is accommodated in the recess 12. The hexagonalportion 6 of the tool can then be pushed into the tool holder 2, and thecollar 4 will be able to pass the latch 7. When the tool is in position,the latch 7 is again pivoted so that the surface 11 projects into thepassage 3 and abuts against the collar 4 if the tool moves in thedirection of the arrow 15.

A second embodiment of a tool retainer is shown in FIG. 4. In thisFigure, similar parts to those shown in FIG. 1 are given the samereference numerals.

In this embodiment, the latch 20 is movable along its own axis betweenactive and inactive positions. The latch 20 has a working surface 21shaped to fit with the collar 4 of the tool, and a projection 22 forhelping to move the latch 20 along its axis. A resilient stoparrangement is indicated at 23. When the narrow or necked down portionof the latch 20 is held by the stop arrangement 23, the surface 21 is inits active position, and will prevent removal of the tool from thesleeve 1.

To move the latch into the inactive position, the projection 22 ispushed away from the sleeve 1 This can be done with the .foot. The stoparrangement 23 disengages and the working surface 21 moves out of thepassage 3'. A secondary stop arrangement is shown at 24,25,26 whichprevents the latch 20 from falling completely out of the sleeve, andfrom falling back into the active postion.

As shown at 18 in FIG. 1, lugs are provided on the end of the sleeve 1which cooperate with correspond ing metal lugs projecting from the toolholder 2. This configuration prevents rotation of the sleeve 1 on thetool holder 2, and also allows the orientation of the latch with respectto the impact machine to be altered, for instance to suit a rightorleft-handed operator.

FIG. 5 shows an alternative arrangement for achiev-' ing the sameobject. Here the tool holder 2 can be placed in four different angularpositions relative the sleeve 1.

In operation, the tool is hit at the rear end of the hexagonal portion 6and the impact thus received is transmitted in the direction shown bythe arrow 15 to the working surface against which the tool is urged bythe machine operator. Normally, the collar 4 does not hit against thesurfaces 11 (FIG. 1) or 21 (FIG. 4) on the outward stroke. However, ifthe tool runs into a soft patch in the working surface, or if there isno surface for it to work against, then the collar 4 will hit thesurface 11 (or 21). If and when the collar 4 reaches the surface 11 (or21), the tool is stopped and the energy is absorbed partly by theresilient sleeve 1, which may stretch a little along the direction 15and partly in the FIG. 1 embodiment by the resilient pivot pin lugswhich may allow the latch to move a small distance relative to thesleeve 1.

An advantage gained by the use of a resilient sleeve is that the metallatch member can be made of a much harder and more wear-resistantmaterial than was hitherto possible. The shock produced by impacts ofthe tool collar on the latch is absorbed by the resilient material andthere is thus a considerably reduced tendency to crack the latch. Thelatch may, for instance, be case-hardened. This makes the metal moresuscepti ble to cracking, but this is not so important with a resilientsleeve.

A resilient sleeve also makes operation of the impacting machine lessnoisy, and contributes towards a lower overall weight of the machine.

What I claim is:

l. A tool retainer for retaining a tool having a shank with a collarthereon, comprising:

a sleeve of resilient material having an axial passage therethrough forreceiving said tool therein,

a latch movably mounted in the sleeve for retaining the tool in thesleeve, the latch having a working surface for abutting the collar ofthe tool to retain the tool, the latch being movable between an activeposition where it projects into the axial passage throughthe sleeve toretain the tool and an inactive position where it is substantiallywithdrawn from said axial passage to allow withdrawal of the tool, and

locking means including a resilient sleeve portion normally projectingin the path of movement of said latch for lockingly engaging said latchin the active position by moving said latch past said projecting sleeveportion, said projecting sleeve portion snapping substantially back toits normal projecting position after passage of said latch, therebylocking said latch in said active position.

2. A tool retainer for retaining a tool having a shank with a collarthereon, comprising:

a sleeve of resilient material having an axial passage therethrough forreceiving said tool therein,

a latch pivotally mounted to the sleeve for retaining the tool in thesleeve, the pivotable latch having a working surface movable uponpivoting of said latch to a working position for abutting the collar ofthe tool to retain the tool, the latch being pivotable to move theworking surface towards and away from the axial passage through thesleeve, and

locking means including a resilient sleeve portion normally projectingin the path of movement of said latch for lockingly engaging said latchin the working position by moving said latch past said projecting sleeveportion, said projecting sleeve portion snapping substantially back toits normally projecting position after passage of said latch, therebylocking said latch in said working position.

3. A tool retainer as claimed in claim 2 comprising a latch pin mountedin part of the resilient sleeve and about which said latch is pivotallymounted, so that impacts of the tool collar on the working surface ofthe latch are, at least partly, absorbed by the resilient latchmounting.

4. A tool retainer as claimed in claim 2 wherein said latch has ahandle, and wherein the locking means comprises two resilient lugshaving a space therebetween, the space having a wider portion of similaror larger cross-section than the handle of the latch, and a narrowerportion through which the handle can only pass when the lugs areresiliently displaced relative to each other.

5. A tool retainer as claimed in claim 3, wherein the sleeve, lockingmeans, and latch pin mounting are all formed from one piece of resilientmaterial.

6. A tool retainer as claimed in claim 2, wherein the end portion of thesleeve which is more distant from the latch includes means for receivinga relatively nonresilient tool holder in which the rear end portion ofthe tool can slide.

7. A tool retainer as claimed in claim 1 wherein the latch is movablealong its own axis.

8. A tool retainer as claimed in claim 3 wherein said latch has ahandle, and wherein the locking means comprises two resilient lugshaving a space therebetween, the space having a wider portion of similaror larger cross-section than the handle of the latch, and a narrowerportion through which the handle can only pass when the lugs areresiliently displaced relative to each other.

9. A tool retainer as claimed in claim 4, wherein the sleeve, lockingmeans and latch pin mounting are all formed from one piece of resilientmaterial.

10. A tool retainer as claimed in claim 2 wherein said sleeve ofresilient material has an opening therethrough to permit said workingsurface of said pivotable latch to pass through said opening into saidaxial passage.

11. A tool retainer as claimed in claim 7 wherein said sleeve ofresilient material has a further passage therethrough, saidfurther-passage extending at an angle relative to said axial passage,said latch being slideably engaged in said further passage and beingmovable along said further passage between said active and inactiveposition.

12. A tool retainer as claimed in claim 11 wherein said locking meanscomprises a first locking means for locking said latch in said activeposition and a second locking means for locking said latch in saidinactive position.

1. A tool retainer for retaining a tool having a shank with a collarthereon, comprising: a sleeve of resilient material having an axialpassage therethrough for receiving said tool therein, a latch movablymounted in the sleeve for retaining the tool in the sleeve, the latchhaving a working surface for abutting the collar of the tool to retainthe tool, the latch being movable between an active position where itprojects into the axial passage through the sleeve to retain the tooland an inactive position where it is substantially withdrawn from saidaxial passage to allow withdrawal of the tool, and locking meansincluding a resilient sleeve portion normally projecting in the path ofmovement of said latch for lockingly engaging said latch in the activeposition by moving said latch past said projecting sleeve portion, saidprojecting sleeve portion snapping substantially back to its normalprojecting position after passage of said latch, thereby locking saidlatch in said active position.
 2. A tool retainer for retaining a toolhaving a shank with a collar thereon, comprising: a sleeve of resilientmaterial having an axial passage therethrough for receiving said tooltherein, a latch pivotally mounted to the sleeve for retaining the toolin the sleeve, the pivotable latch having a working surface movable uponpivoting of said latch to a working position for abutting the collar ofthe tool to retain the tool, the latch being pivotable to move theworking surface towards and away from the axial passage through thesleeve, and locking means including a resilient sleeve portion normallyprojecting in the path of movement of said latch for lockingly engagingsaid latch in the working position by moving said latch past saidprojecting sleeve portion, said projecting sleeve portion snappingsubstantially back to its normally projecting position after passage ofsaid latch, thereby locking said latch in said working position.
 3. Atool retainer as claimed in claim 2 comprising a latch pin mounted inpart of the resilient sleeve and about which said latch is pivotallymounted, so that impacts of the tool collar on the working surface ofthe latch are, at least partly, absorbed by the resilient latchmounting.
 4. A tool retainer as claimed in claim 2 wherein said latchhas a handle, and wherein the locking means comprises two resilient lugshaving a space therebetween, the space having a wider portion of similaror larger cross-section than the handle of the latch, and a narrowerportion through which the handle can only pass when the lugs areresiliently displaced relative to each other.
 5. A tool retainer asclaimed in claim 3, wherein the sleeve, locking means, and latch pinmounting are all formed from one piece of resilient material.
 6. A toolretainer as claimed in claim 2, wherein the end portion of the sleevewhich is more distant from the latch includes means for receiving arelatively nonresilient tool holder in which the rear end portion of thetool can slide.
 7. A tool retainer as claimed in claim 1 wherein thelatch is movable along its own axis.
 8. A tool retainer as claimed inclaim 3 wherein said latch has a handle, and wherein the locking meanscomprises two resilient lugs having a space therebetween, the spacehaving a wider portion of similar or larger cross-section than thehandle of the latch, and a narrower portion through which the handle canonly pass when the lugs are resiliently displaced relative to eachother.
 9. A tool retainer as Claimed in claim 4, wherein the sleeve,locking means and latch pin mounting are all formed from one piece ofresilient material.
 10. A tool retainer as claimed in claim 2 whereinsaid sleeve of resilient material has an opening therethrough to permitsaid working surface of said pivotable latch to pass through saidopening into said axial passage.
 11. A tool retainer as claimed in claim7 wherein said sleeve of resilient material has a further passagetherethrough, said further passage extending at an angle relative tosaid axial passage, said latch being slideably engaged in said furtherpassage and being movable along said further passage between said activeand inactive position.
 12. A tool retainer as claimed in claim 11wherein said locking means comprises a first locking means for lockingsaid latch in said active position and a second locking means forlocking said latch in said inactive position.